守候进程main函数模版及linux守护写法

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#ifdef WIN32

#else
#include <signal.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/resource.h>
#endif//WIN32

#define VERSION_NO "1.0"

int RunProgram()
{
printf("i am running\n");

// do while loop

return 0;
}

#ifdef WIN32
int RunDaemon()
{
//1 run windows daemon

//2 use CreateMutex to make sure program have only one instance

//3 RunProgram
RunProgram();

return 0;
}

#else

int RunDaemon()
{
struct sigaction act;
struct rlimit    rl;

//
pid_t processID      = 0;
int   status         = 0;
int   pid            = 0;

// ignore signal
act.sa_flags = 0;
act.sa_handler = SIG_IGN;
(void)::sigaction(SIGPIPE,  &act, NULL);
(void)::sigaction(SIGHUP,   &act, NULL);
(void)::sigaction(SIGINT,   &act, NULL);
(void)::sigaction(SIGTERM,  &act, NULL);
(void)::sigaction(SIGQUIT,  &act, NULL);
(void)::sigaction(SIGALRM,  &act, NULL);

//set max file handle count
rl.rlim_cur = 10240;
rl.rlim_max = 10240;
setrlimit(RLIMIT_NOFILE, &rl);

//set core dump size
rl.rlim_cur = RLIM_INFINITY;
rl.rlim_max = RLIM_INFINITY;
setrlimit(RLIMIT_CORE, &rl);

//run in background
if (daemon(0,0) != 0)
{
exit(-1);
}

while(true)
{
processID = fork();
if(processID > 0)
{
status = 0;
while(status==0)
{
pid =::wait(&status);
int exitStatus = WEXITSTATUS(status);
if(WIFEXITED(status) && pid > 0 && status != 0)
{
if(exitStatus == -1)
{
printf("child exit\r\n");
exit(EXIT_FAILURE);
}
printf("[RunDaemon] - WIFEXITED\r\n");
break;
}
if(WIFSIGNALED(status))
{
printf("[RunDaemon] - WIFSIGNALED\r\n");
break;
}
if(WIFSTOPPED(status))
{
printf("[RunDaemon] - WIFSTOPPED\r\n");
break;
}
if(pid == -1 && status == 0)
{
continue;
}
if(pid > 0 && status == 0)
{
printf("[RunDaemon] - status == 0\r\n");
exit(EXIT_SUCCESS);
}
printf("[RunDaemon] - EXIT_FAILURE\r\n");
exit(EXIT_FAILURE);
}
}
else if(processID == 0)
{
break;
}
else
{
exit(EXIT_FAILURE);
}
sleep(1);
}

if(processID != 0)
{
exit(EXIT_SUCCESS);
}
else
{
RunProgram();
}

return 0;
}

#endif//WIN32

int main(int argc, char *argv[])
{
bool bExit = false;

if (
(argc >= 2)
&& (strcmp(argv[1], "-v") == 0)
)
{
printf("MyProgram %s %s %s\r\n", VERSION_NO, __DATE__, __TIME__);
bExit = true;
}

if (!bExit)
{
RunDaemon();
}

return 0;
}